This invention relates to a seal adapted to be used for track link connections for construction vehicles such as bulldozers and the like.
One of the conventional seal rings which has been employed in the seals of the kind specified comprises, as disclosed in U.S. Pat. No. 3,841,718, a driving flange, a sealing flange and a bight portion of a thin wall thickness connecting the two flanges.
When this seal ring is set together with a load ring in the counterbore defined by a bushing and a link, because the thickness of the bight portion is thin, the bight portion tends to deform inwardly to a large extent and contacts with a thrust ring so that the inclination of the load-deflection curve will change and therefore required stable load-deflection characteristics can not be obtained. Further, because the seal ring of the above-mentioned type has a small rigidity, when it is set in loaded position, the seal flange tends to be subjected to an abnormal deformation, thus causing earlier weardown of the sealing surface.
Another type of seal assembly is disclosed in U.S. Pat. No. 4,062,550, the assignee of which is the same as that of the present application. However, it revealed by the results of later experiments that the seal ring of this type could not exhibit such a durability as expected. The reason envisaged for it is that, because the sealing flange of the seal ring is kept into contact with the end face of the bushing in a wide sealing surface, there is a tendency of occurrence of oil leaks.